A semiconductor integrated circuit device can be utilized in a variety of desired manners based on identification information unique thereto, if such identification information is assigned. If unique identification information can be set to semiconductor integrated circuit devices on a one-by-one basis, a novel manufacturing method and product management technique, demonstrated by the inventors, can be provided under the utilization of the unique identification information, as described later.
When a fault occurs at a stage such as an actual use stage of a semiconductor integrated circuit device, factors causing the fault is readily pursued if unique identification information can be retrieved from the semiconductor integrated circuit device. For example, a semiconductor maker can acquire information such as the manufacturing term, manufacturing line, manufacturing lot, testing history, design information and the like based on the unique identification information of the semiconductor integrated circuit device. This facilitates the pursuit of factors which cause the fault and countermeasures to be taken therefor.
The marking based on an ink printing method or a laser impressing method given to a package, which forms part of a semiconductor integrated circuit device, can be regarded as one type of identification information. While this type of marking mainly comprises a product model name of the semiconductor integrated circuit device, the product model name may be accompanied by a code representation of the manufacturing term such as year, week and the like. However, with this type of marking representation, it is difficult to set unique identification information to semiconductor integrated circuit devices on a one-by-one basis, which can be manufactured in large quantity or manufactured over a long term as industrial products, due to the shortage of the amount of information which can be represented thereby.
It can be assumed to set a programmable element such as a fuse element to a semiconductor chip which forms part of a semiconductor integrated circuit device and to give unique identification information inherent to the programmable element. However, if the original semiconductor integrated circuit device does not need a program element, this type of assumable technique would disadvantageously cause a complicated manufacturing process and an increased cost of the semiconductor integrated circuit device due to the requirement for an additional manufacturing step for the programmable element. The manufacturing process will be free from additional complication if the semiconductor integrated circuit device originally has a programmable element. Even in this case, an additional or modified manufacturing step is needed for writing unique recognition information into the programmable element.
In a know technique referred to as “silicon signature,” a product model name or unique information is written into a semiconductor integrated circuit device in such a manner that they can be electrically read out. However, this type of technique requires an additional or modified manufacturing step for writing the information, as is the case with the foregoing.
The inventors were informed, through an investigation after the present invention had been made, that inventions described in JP-A-6-196435, JP-A-10-055939, JP-A-11-214274, JP-A-7-335509, and JP-A-7-050233 existed as related to the present invention, later described. Either of the inventions described in the official documents is recognized to require an extra manufacturing step for writing unique identification information into each chip. However, these official documents are not recognized to include any description related to a method for identifying a semiconductor integrated circuit device which does not particularly require an additional or a modified manufacturing step as the present invention, later described.
It is therefore an object of the present invention to provide a semiconductor integrated circuit device or a semiconductor chip which can be individually identified in a simple configuration, and a method for identifying a semiconductor integrated circuit device or a semiconductor chip. It is another object of the present invention to provide a semiconductor integrated circuit device which is capable of identifying individual semiconductor integrated circuit devices or semiconductor chips with a high reliability. It is a further object of the present invention to provide a rational method for manufacturing a semiconductor integrated circuit device. The above and other objects and novel features of the present invention will become apparent from the description of the specification and the accompanying drawings.